With the -4 as n = 1. . .
The bottoms are just 3^(n-1).
Look at the tops. See how they're all just the bottoms - 5?
1 - 5 = -4
3 - 5 = -2
27 - 5 = 22
81 - 5 = 76
243 - 5 = 238
So the tops are just 3^(n-1) - 5
Answer: The nth term is ( 3^(n-1) - 5 ) / ( 3^(n-1) )